Adaptor boxes are used for mounting low voltage lighting fixtures to a low voltage track. As well recognized, such adaptor boxes must not only provide reliable mechanical support for the lighting fixture but also reliable electrical connection. As such fixtures typically operate on only 12 volts, even a small voltage drop at the connection to the track may result in a discernable effect on the operation of the light fixture.
At the same time the adaptor boxes should be of desirably small size with few parts, affording economic manufacture and assembly at high volume.
A conventional type of low voltage lighting track has an insulating body formed by an elongate web joining conventional flanges, from respective free ends of which protrude inward mounting edge portions or lips defining a generally channel form cavity for receiving a mounting head portion of the adapter box. Conventional conductive wire busses are mounted on respective ears adjacent the junction of the flanges and the web.
A conventional type of adaptor box assembly comprises a contact housing assembly having a mounting head for mounting in the cavity by opposed ears thereof engaging over respective lips, separated contacts terminating fixture wires in the housing assembly and extending through an opening or passageway in the head for connection to respective track wires; a wire guide assembly, and a releasable latching member extending between the lips to prevent accidental rotation of the head which would disengage the ears, demounting the adaptor box from the track.
A widely used adaptor box of the type described above is disclosed in U.S. Pat. No. 5,334,037 issued Aug. 2, 1994 to Gabrius et al., the disclosure of which is incorporated herein by reference. The reference teaches that adaptor box housing should be formed by two, separately molded, housing halves, subsequently assembled with their open faces abutted together, and secured by a screw passing through both housing halves. A contact separator is molded in one piece in the contact opening or passageway of one housing half, permitting the contacts to be preassembled in the housing in separated positions by insertion through the open face, to extend through the contact opening on opposite sides of the contact separator, and the housing halves subsequently secured together. The rotation preventing latch is also a separately molded element subsequently mounted on one of the housing halves. A wire guide assembly comprises several components which are secured together by a rivet and require access provided by an open face for preassembly in the housing half.
Thus, the prior adaptor box consists of many different parts which require separate manufacture and several assembly steps while the integrity of the overall structure depends on the effectiveness of a single screw fastening between plastic housing halves.